engineering recuitment GATE CSE 2023-24 Test Series DBMS Integrity Constraints and Normal Form Normal Form
Consider the relation R(P, Q, S, T, X, Y, Z, W) with the following functional dependencies.
PQ → X; P → YX; Q → Y; Y → ZW
Consider the decomposition of the relation R into the constituent relations according to the following two decomposition schemes.
D1 : R = [(P, Q, S, T); (P, T, X); (Q, Y); (Y, Z, W)]
D2 : R = [(P, Q, S); (T, X); (Q, Y); (Y, Z, W)]
Which one of the following options is correct?
1
D1 is a lossy decomposition, but D2 is a lossless decomposition.
2
Both D1 and D2 are lossless decompositions.
3
Both D1 and D2 are lossy decompositions.
4
D1 is a lossless decomposition, but D2 is a lossy decomposition.